A capillary gas chromatographic procedure is described for the determination of cyclohexanone leached from hemodialysis tubing by water. Recoveries were 100% at 2.0 mg/100 mL (20 ppm), 99.0% at 500 microg/100 mL (5 ppm), and 106% at 1.0 microg/100 mL (10 ppb). Reproducibility of the system was 0.152% for 3.0 microL injections of a solution containing cyclohexanone at 5.58 microg/mL. Correlation coefficients were 0.9983 for 0.3672-3.672 ng and 1.0000 for 3.672-367.2 ng. Twenty hemodialysis tubing sets from 4 manufacturers were examined. The leachable cyclohexanone ranged from 1.02 to 43.7 ppm per set. Rinsing the tubing with 1 L 0.9% sodium chloride solution did not remove significant amounts (P = 0.05) of leachable cyclohexanone.